Mobil Badger process, zeolite catalysts

EBMax A continuous, liquid-phase process for making ethylbenzene from ethylene and benzene, using a zeolite catalyst. Developed by Raytheon Engineers and Constructors and Mobil Oil Corporation and first installed at Chiba Styrene Monomer in Japan in 1995. Generally similar to the Mobil/Badger process, but the improved catalyst permits the reactor size to be reduced by two thirds. 

ABB Lummus Crest Inc. and Unocal Corp. have licensed a benzene alkylation process using a proprietary zeolite catalyst. Unlike the Mobil-Badger process, the Unocal-Lummus process is suitable for either ethylbenzene or cumene manufacture (27,28). 

Alkylation. In the field of alkylation of benzene with ethene zeolite-based catalysts are used for the past 20 years, replacing the conventional A1C13- and BF3-on-alumina based processes. Here the question in case of a new plant is not whether a zeolite-based process will be selected but rather which one to choose. The Mobil-Badger process uses ZSM-5 as the catalyst and is the most widely applied though recently other zeolites (Y, Beta and MCM-22) have come to the fore. 

Application To produce cumene from benzene and any grade of propylene—including lower-quality refineiy propylene-propane mixture—using the Mobil/Badger process and a new generation of zeolite catalysts from ExxonMobil. 

Mobil/Badger Ethylbenzene Benzene, polymer-grade ethylene EBMax process uses proprietary Mobil MCM-22 zeolite catalyst low capital cost 10 2000... 

Table 8.2 presents comparatively the four reactor types proposed above. Liquid-phase alkylation was practiced in the past, but is nowadays completely obsolete, mainly because of pollution problems. Vapour-phase alkylation (UOP Alkar process) was popular up to 1970, when Mobil/Badger process based on ZMS-5 synthetic zeolite catalyst was launched. This process dominates the market nowadays, but is in competition with the liquid-phase process based equally on zeolite catalyst proposed by UOP/Lummus. The two processes have similar performances. The selection depends greatly on the catalyst behaviour, price and regeneration cost. We would prefer the last, for the following reasons ... 

Alkylation by zeolites made a major entry in the field of industrial catalysis through the highly acclaimed Mobil-Badger process for ethylbenzene (Csicsery, 1984, Hoelderich et al., 1988 Hoelderich and Van Bekkum, 1991) by replacing the toxic, eco-unfriendly, corrosive Friedel-Crafts reaction. A modified version developed by the National Chemical Laboratory (the Albene process), using a similar class of catalysts known as Encilites, is particularly suited to alkylation by ethyl alcohol of any concentration down to 30% (Bhowmik and Ratnasamy, 1991). 

The alkylation of benzene with ethylene in the gas phase was first achieved in 1942. Initially, Al203/Si02 was used as a catalyst, but this was replaced later by P40io/Si02. However, transalkylation is not complete when these catalysts are applied and the yield is unsatisfactory. Since 1980, zeolite catalysts have found application in gas-phase production of ethylbenzene. The Mobil-Badger process uses a ZSM-5-zeolite catalyst at a temperature of 420 to 430 °C and a pressure of... 

Zeolites are replacing acid catalysts in a number of manufacturing processes. One of the most important is the alkylation of aromatics. The Mobil-Badger process for producing CgHsEt from CgHg and C2H4 provides the... 

Among the wide variety of organic reactions in which zeolites have been employed as catalysts, may be emphasized the transformations of aromatic hydrocarbons of importance in petrochemistry, and in the synthesis of intermediates for pharmaceutical or fragrance products.5 In particular, Friede 1-Crafts acylation and alkylation over zeolites have been widely used for the synthesis of fine chemicals.6 Insights into the mechanism of aromatic acylation over zeolites have been disclosed.7 The production of ethylbenzene from benzene and ethylene, catalyzed by HZSM-5 zeolite and developed by the Mobil-Badger Company, was the first commercialized industrial process for aromatic alkylation over zeolites.8 Other typical examples of zeolite-mediated Friedel-Crafts reactions are the regioselective formation of p-xylene by alkylation of toluene with methanol over HZSM-5,9 or the regioselective p-acylation of toluene with acetic anhydride over HBEA zeolites.10 In both transformations, the p-isomers are obtained in nearly quantitative yield. 

In recent years alkylations have been accomplished with acidic zeolite catalysts, most nobably ZSM-5. A ZSM-5 ethylbenzene process was commercialized jointly by Mobil Co. and Badger America in 1976 (24). The vapor-phase reaction occurs at temperatures above 370°C over a fixed bed of catalyst at 1.4—2.8 MPa (200—400 psi) with high ethylene space velocities. A typical molar ethylene to benzene ratio is about 1—1.2. The conversion to ethylbenzene is quantitative. The principal advantages of zeolite-based routes are easy recovery of products, elimination of corrosive or environmentally unacceptable by-products, high product yields and selectivities, and high process heat recovery (25,26). 

Zeolite-Based Alkylation. Zeolites have the advantage of being noncot-rosive and environmentally benign. The Mobil-Badger vapor-phase ethylbenzene process was ihe lirsl zeolite-based process to achieve commercial success. It is based on a synthetic zeolite catalyst. ZSM-5. and has the desirable characteristics of high activity, low oligomerization, and low coke formation. See also Molecular Sieves. 

Alkylation. Ethylbenzene [100-41-4], the precursor of styrene, is produced from benzene and ethylene. The ethylation of benzene is conducted either in the liquid phase in the presence of a Friedel-Crafts catalyst (A1C13, BF3, FeCl3) or in the vapor phase with a suitable catalyst. The Monsanto/Lummus process uses an aluminum chloride catalyst that yields more than 99% ethylbenzene (13). More recently, Lummus and Union Oil commercialized a zeolite catalyst process for liquid-phase alkylation (14). Badger and Mobil also have a vapor-phase alkylation process using zeolite catalysts (15). Almost all ethylbenzene produced is used for the manufacture of styrene [100-42-3], which is obtained by dehydrogenation in the presence of a suitable catalyst at 550—640°C and relatively low pressure, <0.1 MPa (<1 atm). 

Over the past seven years, cumene producers have begun to convert to the more environmentally friendly and more efficient zeolite-based processes. Principal among these are processes licensed by Dow, CDTech, Mobil-Badger, Enichem, and UOP. The zeolite based processes produce higher cumene yields than the conventional SPA process because most of the diisopropylbenzene byproduct is converted to cumene in separate transalkylation processes. Operating and maintenance costs are reduced because there is no corrosion associated with the zeolite catalysts. Finally, environmental concerns associated with the disposal of... 

The first commercial plant based on the Mobil/Badger vapor phase technology was commissioned in 1980. From 1980 until the early 1990s, use of the vapor phase process gained in popularity because it offered several advantages over the aluminum chloride process. A major benefit of the vapor phase process was the use of a zeolite catalyst that eliminated the issues associated with corrosion and waste disposal of aluminum chloride. 

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